Activists decried ACTA as the spiritual successor to America’s hated (and defeated) Stop Online Piracy Act, a bill which would have given copyright holders and the government broad powers to shut down websites suspected of involvement with illegal file sharing.

Among the signatories was Poland, which saw massive protests against ACTA yesterday.

A host of other countries already signed the agreement last year, including Japan, Canada, Australia, and the United States.

Critics describe ACTA resoundingly as a threat to Internet freedoms masquerading as a trade agreement. Ostensibly a means of streamlining copyright law across nations, it has language that can be interpreted to allow the prosecution of people who “aid and abet” the sharing of files online. Its punishments can be severe, including prison sentences.